Aroma diffuser



FIG. 1 is a perspective view of an aroma diffuser showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings represent portions of the aroma diffuser that form no part of the claimed design. 

CLAIM The ornamental design for an aroma diffuser, as shown and described. 